0000000000697054
AUTHOR
Jan Elbers
showing 3 related works from this author
Quantification of land-atmosphere exchanges of water, energy and carbon dioxide in space and time over the heterogeneous Barrax site
2008
International audience; To advance our understanding of land-atmosphere exchanges of water, energy and carbon dioxide (CO2) in space and time over heterogeneous land surfaces, two intensive field campaigns were carried out at the Barrax agricultural test site in Spain during 12-21 July 2004 (SPARC 2004) and 8-14 July 2005 (SEN2FLEX 2005) involving multiple field, satellite and airborne instruments for characterizing the state of the atmosphere, the vegetation and the soil from the visible to the microwave range of the spectrum. Part of the experimental area is a core site of area 25 km2, within which numerous crops are grown, on both irrigated and dry land, alongside fields of bare soil. Th…
HAPEX-Sahel
1997
The variation in evaporative fraction and actual evaporation is examined for three sample days in the HAPEX-Sahel Intensive Observation Period (IOP), including data from all the vegetation types and sites. The trends in evaporative fraction over the IOP are also presented for eight sites. The high rate of evaporation from bare soil in the days following rainfall produces a variability in evaporation which makes differences between sites difficult to interpret on a day-to-day basis, but over the whole IOP it is shown that the millet uses a smaller proportion of the available energy for evaporation than the tiger bush or fallow savannah. The combined effect of differences in the total energy …
Remote sensing of sun-induced fluorescence to improve modeling of diurnal courses of gross primary production (GPP)
2010
Terrestrial gross primary production (GPP) is an important parameter to explore and quantify carbon fixation by plant ecosystems at various scales. Remote sensing (RS) offers a unique possibility to investigate GPP in a spatially explicit fashion; however, budgeting of terrestrial carbon cycles based on this approach still remains uncertain. To improve calculations, spatio-temporal variability of GPP must be investigated in more detail on local and regional scales. The overarching goal of this study is to enhance our knowledge on how environmentally induced changes of photosynthetic light-use efficiency (LUE) are linked with optical RS parameters. Diurnal courses of sun-induced fluorescence…